Stationary slick line pumping method

ABSTRACT

An alternative apparatus and pumping method for retrieving liquids from a wellbore without the use of a pumping unit as customarily used in oil field operations.

FIELD OF THE INVENTION

The present invention relates to an alternative apparatus and pumpingmethod for retrieving liquids from a wellbore without the use of apumping unit as customarily used in oil field operations. This unit isprimarily targeted for gas well deliquification and/or low fluid volumeoil or condensate wells.

BACKGROUND OF THE INVENTION

In typical oil field operations, when liquids are recovered from oil andgas wells, the wells are equipped with a pumping unit which reciprocatessucker rods upwardly and downwardly in the well to activate a down-holepump which pumps liquids, such as oil, water and mixtures thereof, tothe surface. The maintenance of such equipment is relatively expensive,as is the equipment itself. Further in relatively low production wellsit is continually necessary to adjust the speed and run time of thepumping unit, and the like to keep the level of the well liquids abovethe top of the pump. It is detrimental to operate a pump above the levelof the liquid.

In many instances, it is desirable to remove liquids from a wellbore bya different approach. The different approach is desirably one which doesnot require the use of the expensive equipment or the continuedadjustments based upon the level of liquids in the well.

Accordingly, a continuing search has been directed to a method foreffectively removing liquids from such wells.

SUMMARY OF THE INVENTION

According to the present invention, such liquids are readily recoveredby an apparatus for recovering liquids from a well containing a tubularmember having an inside and extending from an earth surface to penetratea liquid producing subterranean formation, the apparatus comprising: abody having a body top and a body, a round exterior surface, openings inthe body top and a valve in the body; a flexible support memberextending from a system for raising and lowering the flexible supportmember in the wellbore and connected to the body top.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a prior art pumping system forrecovering liquids from a subterranean liquid producing formation;

FIG. 2 is a schematic diagram of an embodiment of the present invention;

FIG. 3 is a schematic diagram of a further embodiment of the presentinvention;

FIG. 4 is a schematic diagram of an embodiment of a body used to liftliquids according to the embodiment of the present invention;

FIG. 5 is a schematic diagram of an alternate and larger embodiment ofthe body to use to lift liquids according to the embodiment of thepresent invention;

FIG. 6 is a schematic diagram of a further alternate apparatus forproducing liquids; and,

FIG. 7 is a schematic diagram of a system useful for raising andlowering a slick line, wire line, copper tubing or the like into andretrieving the line from a well.

DESCRIPTION OF PREFERRED EMBODIMENTS

In the discussion of the Figures, the same numbers will be usedthroughout to refer to the same or similar components.

In FIG. 1 an embodiment of a prior art apparatus for the production ofliquids from a subterranean formation is shown. A well 10 is shownextending from an earth surface 12 through an overburden 14 to a liquidbearing formation 16. The well includes a casing 18 which is cementedinto place by cement 20 with the casing having an inside 19.Perforations 22 are positioned through casing 18 in the liquid producingformation and a pump 24 is positioned to pump fluids to the surfacebased upon reciprocal motion of sucker rods 26. The fluids are producedthrough a production tubing 28 having an inside 30 through which theliquid is pumped and discharged through a production flow line 32. Aliquid level 34 is desirably maintained in well 10 above the top of pump24 for operations. The well may include a tubing anchor catcher andcentralizer at a position in the lower portion of the tubing. Such atubing catcher and centralizer are shown at 39.

In FIG. 2 an embodiment of the present invention is shown. The pump 24and sucker rods 26 are no longer needed however a seal 38 is positionedin the top of production tubing 28 to permit the entry and movement of aflexible slick line 40 or the like through the seal. “Slick line” refersto a flexible solid wire which may be used to raise and lower apparatusin a production casing or in a production tubing. Other equipment whichcould be used for such purposes comprises wire lines, braided steelline, plastic line, and other various materials. The use of the term“wire line” is used to refer to a wire like flexible material which maycomprise a plurality of strands.

The present invention comprises a body 42, which is shown positionedbeneath the liquid level 34. The body is connected via a slick line 40to a system for raising the body in the production tubing. The body 42includes a top 44 and a bottom 46. The body is lowered to a positionnear the bottom 52 of the well. Desirably the body is lowered to aposition beneath perforations 22 into subterranean formation 16. Furtherit may be desirable that seals (not shown) be positioned around theoutside surface of the body to minimize the amount of fluid that willleak between the body 42 and tubing 28.

In the operation of the apparatus shown in FIG. 2, liquids are shown tohave accumulated to a level 34 in well 10. These liquids may bepetroleum, petroleum distillates, water, mixtures thereof and the like.It may be desirable from time to time to recover these liquids.Especially if the well is a relatively low production well, it may notbe feasible to maintain a pumping unit at the well so alternate methodsof producing these liquids are necessary if the well is to be producedat low, although profitable, levels. The body is positioned so that whenraised by the slick line it moves liquids in production tubing 28upwardly through the well for production through the production flowline 32.

The body in its raised position is shown in FIG. 3 with the well havinga reduced level 34. The body may then be lowered into well 10 and isadapted to readily sink into production tubing 28 through the liquid forretrieval to remove additional liquid from the well.

An embodiment of the body 42 is shown in FIG. 4 and, as shown, includesholes 72 in its top through which liquid can flow as shown by arrows 85.Liquid flow into the body is shown by arrow 84. A slick line wire isshown connected to a connector 70 on the top of body 42. As the body 42is lowered into the liquid, pressure under the ball 50 forces the ballto un-seat from the ball seat 48. The action between ball 50 and seat 48acts as a ball and seat valve. Liquid can thus flow into and through thebody to permit readily lowering the body through a liquid level. Ifunusual or extreme conditions exist within well 10 rubber or plasticseals (not shown) would be placed in the machined grooves 78 on theoutside of the tool 42. The top 44 and bottom 46 of the body 42 areconnected by the threaded section 47 at the top of part 46. Machinedchannels 49 allow for wrenches to tighten part 44 to part 46 withoutaffecting the close tolerance of the tool 42 and the tubing 28. FIG. 5is an alternative embodiment of FIG. 4 in that it is a larger diametertool for use in larger diameter tubing.

In FIG. 6 an alternate embodiment of the body shown in FIGS. 4 and 5 isshown. This embodiment is shown in a position for lowering the body intoa liquid. Further, seals not shown in this embodiment are slightlydifferent and comprise seals similar to o-rings seated in grooves 78 ina wall of the body 42

A variety of seals of different configurations can be used with equalsuccess. The seals shown are considered to be illustrative of the use ofseals and it should be noted that the drawings are not drawn to scale.In a preferred embodiment, the mechanical clearance between the outsideof body 42 and inside 30 of production tubing 28 is maintained at veryclose tolerances. This permits the withdrawal of the liquid effectivelyby the use of the body without respect to the seals.

In some applications, it is desirable to have seals rather than closertolerances since it is considered that the seals can be more effectivelylowered into the liquid layer than can a very tightly toleranced body.Typically when no seals are used it is desirable that the clearancebetween an outer surface of the body 42 and the inside surface of theproduction tubing be such that a very small amount of liquid would flowpast the body 42. Somewhat larger tolerances between outer surface andthe inside of the production tubing may be used when seals are usedsince the seals will facilitate prevention of leakage of liquids pastthe body.

In FIG. 7 a system is shown for lowering the slick line into the well.Slick line 40 is passed over a roller and mounting bracket 56 andaccumulated on or discharged from a slick line drum 58. As indicatedpreviously, wire lines, polymer lines and the like may be used in lieuof the slick line. The wire line drum is supported on a support 60 andincludes a pulley 62 which is driven by a belt 68 from a motor 64, whichis preferably an electric motor, which is supported on a stand 66. Thestand 66 is either mounted to a cement foundation or directly to theground. Other configurations can be used for this operation as wellknown to those skilled in the art.

The operation of the apparatus of the present invention is effective tolower the body into a well through a layer of liquid and to withdraw thebody upwardly through the well to discharge liquids through a recoveryline. This permits the recovery of significant amounts of liquids fromwells which may not produce enough liquid to justify maintaining pumpingunit equipment at the well. Further it does not require extensivecontrol of the level since if the level rises too high it will simply berecovered through the recovery line 32 and the well can then be emptiedusing the slick line and the body at intervals as desired. The alternatepumping system of the present invention can also be used to operatewells of higher production but more frequent operation of the recoverycycle is necessary. Further the recovery cycle can be automated to runat selected intervals with only infrequent attention from the operatoralthough it is anticipated that the operator of the well willperiodically operate the well manually as required. This applicationalso allows the operator of low liquid volume wells to set thisapplication below perforations 16 if desired to further lower thebottom-hole pressure. Currently with most other forms of artificiallift, it is not recommended to set the pump intake below theperforations.

A further application of the present invention is the removal of liquidswhich may accumulate in low pressure gas wells. In such wells, the gasmay be produced at a pressure sufficiently low that it will not flowupwardly through the liquid layer. In such instances, lowering theliquid layer to a sufficiently low level is crucial to the production ofthe natural gas. Accordingly, it is clear that the apparatus of thepresent invention and the method of the present invention can be usedfor a variety of purposes such as the operation of recovery from arelatively high producing well to recovery of liquids from a relativelylow producing well or for the removal of undesired liquids from lowpressure gas wells.

Furthermore this application lends itself to be powered by a standardelectricity source such as power lines, or by alternative energy sourcessuch as solar power, wind generators or any other alternative energysource that generates clean reliable energy.

While not discussed above, it will be understood that the apparatus ofthe present invention could also be used inside a casing as it is usedinside production tubing. In such instances, the body must be configuredto suitably interact with the inside surface of the casing. In otherrespects the operation is the same as discussed above for operation ofproduction tubing. This may also be desirable in some wells since it maybe used in wells which are not fully completed or from which the tubinghas been withdrawn. In some instances it may be desirable to limit theamount of liquid which is positioned for removal by the slick linewithdrawal. Weight considerations may require that the amount of liquidwhich could be moved upwardly by the body be limited to the weightlifting capacity of the slick line.

The liquids recovered are typically petroleum, petroleum distillates,water, brine, and mixtures thereof. The gas recovered typicallycomprises natural gas. The recovery of these valuable materials isfacilitated by the use of the present invention in instances where it isnot desirable or feasible to use a pumping unit with a submersible pumpand the like.

While the present invention has been described by reference to certainof its preferred embodiments, it is pointed out that the embodimentsdescribed are illustrative rather than limiting in nature and that manyvariations and modifications are possible within the scope of thepresent invention. Many such variations and modifications may beconsidered obvious and desirable by those skilled in the art based upona review of the foregoing description of preferred embodiments.

1. An apparatus for recovering liquids from a well containing a tubularmember having an inside and extending from an earth surface to penetratea liquid producing subterranean formation, the apparatus comprising: a)a body having a body top and a body, a round exterior surface, openingsin the body top and a valve in the body; b) a flexible support memberextending from a system for releasing and retrieving the flexiblesupport member in the wellbore and connected to the body top
 2. Theapparatus of claim 1 wherein the valve is a ball valve.
 3. The apparatusof claim 1 wherein the valve is a flapper valve.
 4. The apparatus ofclaim 1 wherein the tubular member is a production tubing.
 5. Theapparatus of claim 1 wherein the body top includes at least one hole. 6.The apparatus of claim 1 wherein the flexible support member comprisesat least one of a braided wire line, slick line and polymer line.
 7. Theapparatus of claim 1 wherein the clearance between the outside of thebody and the inside of the tubular member is a tight mechanicaltolerance such that minimal fluid will pass by the outside of the body.8. The apparatus of claim 1 wherein seals are positioned on the exteriorsurface of the body to reduce leakage of fluids between the outside ofthe body and the inside of the tubular member.
 9. The apparatus of claim1 wherein the tubular member is a casing.
 10. A method for producingfluids from a well containing a tubular member having an inside andextending from an earth surface to penetrate a fluid producingsubterranean formation, the method comprising: a) positioning anapparatus comprising a body having a body top and a body, a roundexterior surface, openings in the body top and a valve in the body inthe well; b) connecting the apparatus to a flexible support member tolift and lower the body; c) producing liquids from the well by raisingthe body; and, d) lowering the body into the well.
 11. The method ofclaim 11 wherein the fluid comprises at least one of petroleum,distillates, water and natural gas.
 12. The method of claim 11 whereinthe well is a low fluid production well producing at least petroleum,natural gas, distillates and water.
 13. The method of claim 11 whereinthe tubular member is a production tubing and wherein liquids areproduced by lifting the body through the production tubing.
 14. Themethod of claim 11 wherein the tubular member is a casing and whereinliquids are produced by lifting the body through the casing.
 15. Themethod of claim 11 wherein the well is a low pressure gas well whichalso produces liquids wherein the liquids are removed to enable theproduction of gas.
 16. The method of claim 11 wherein the body islowered by opening the valve and allowing liquids to flow into the bodyand out of the body through the valve and at least one hole in the bodytop.
 17. The method of claim 11 wherein natural gas is produced from thewell by periodic removal of liquids.
 18. The method of claim 11 whereinthe flexible support member comprises a wire line, slick line or polymerline.